Effect of climate on strategies of nest and body temperature regulation in paper wasps, Polistes biglumis and Polistes gallicus

Anton Stabentheiner,Julia Magdalena Nagy,Iacopo Petrocelli,Helmut Kovac,Helmut Käfer,Stefano Turillazzi

doi:10.1038/s41598-022-07279-0

Anton Stabentheiner, Julia Magdalena Nagy + Show 4 more

Open Access

https://doi.org/10.1038/s41598-022-07279-0

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Abstract

Polistes paper wasps are a widespread taxon inhabiting various climates. They build nests in the open without a protective outer layer, which makes them vulnerable to changing temperatures. To better understand the options they have to react to environmental variation and climate change, we here compare the thermoregulatory behavior of Polistes biglumis from cool Alpine climate with Polistes gallicus from warm Mediterranean climate. Behavioral plasticity helps both of them to withstand environmental variation. P. biglumis builds the nests oriented toward east-south-east to gain solar heat of the morning sun. This increases the brood temperature considerably above the ambience, which speeds up brood development. P. gallicus, by contrast, mostly avoids nesting sites with direct insolation, which protects their brood from heat stress on hot days. To keep the brood temperature below 40–42 °C on warm days, the adults of the two species show differential use of their common cooling behaviors. While P. biglumis prefers fanning of cool ambient air onto the nest heated by the sun and additionally cools with water drops, P. gallicus prefers cooling with water drops because fanning of warm ambient air onto a warm nest would not cool it, and restricts fanning to nests heated by the sun.

Highlights

Polistes paper wasps are a widespread taxon inhabiting various climates
The size of thermographed nests was quite variable in both species, the number of cells ranging from 18 to 99 in P. biglumis, and from 19 to 381 in P. gallicus (Table S1)
The behavioral plasticity of P. gallicus is reflected in the flexibility concerning nesting site choice: the bimodal distribution we found, with α = 134° (~ SE) and α = 32° (~ NNE) (Fig. 7), differs from the mean orientation of α = 102° in a Spanish population nesting on p lants[39], and α = 150° in Spanish urban environments[52]

Summary

Introduction

Polistes paper wasps are a widespread taxon inhabiting various climates. They build nests in the open without a protective outer layer, which makes them vulnerable to changing temperatures. To better understand the options they have to react to environmental variation and climate change, we here compare the thermoregulatory behavior of Polistes biglumis from cool Alpine climate with Polistes gallicus from warm Mediterranean climate. In Polistes paper wasps, any active (metabolic) heating effort of the adults would mean much wasted energy because the heat is immediately lost to the surrounding air[14,16–19] They have to regulate the nest temperature by behavioral means, which includes nest site choice as an initial, ‘forward-looking’ s trategy[20–24]. To shed light on the thermoregulatory ability of these Polistes species, we here compare the effect of environmental difference and variation in temperature and radiation on these wasps’ body and brood temperature, on their behavioral measures of brood temperature control, and on their choice of nesting sites

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